In the supermarket you return a cart to the cart area. you stand still and push the cart towards the other carts. you’ve just learned that the cart pushes back on you too, according to newton’s third law. a. explain why the cart moves and you do not. hint: consider the cart and yourself separately. also consider all the forces acting on you and on the cart. b. is the cart in equilibrium once you let go of the handle? explain.